two bit idiot is one of my favourite writers on cryptocurrencies. In this article he makes a good attack on cryptocurrency index funds.
Cryptocurrency Index Funds are needed
It is an excellent article but being an active investor he has rather missed the point. Because as a passive investor the CrytoIndex Guru does not seek the best possible return, only an average market return at minimal cost.
This site has great resources to help you learn more about passive investment in cryptocurrency indexes, funds and how manage your own portfolio.